Flueric self-biasing and gate

ABSTRACT

A flueric AND logic element is disclosed which is capable of accurate and reliable operation without the necessity of critical dimensional control. This is accomplished by the use of a pair of fluid bias channels which produce a low pressure region in the vicinity of the control nozzle. In one embodiment the bias channels are located between the two input signals and the two control channels of the respective amplifiers. In a second embodiment both bias channels feed into a central control channel located between the two interaction chambers of the respective amplifiers.

United States Patent [72| Inventors Hear Steven Klmtnel 3.426.783 2/1969 Campagnuolo 137/81 5 GI M -z 3.442.279 5/1969 Swartz, 137/81 5 Elmer L. Sllfll. Annnndnle. VI. $544,876 5/1969 Sicrnch et a1v 137/8l .5 I21] ApplNu 81 .8 1 3.468.326 9/1969 Cohen... 137/815 122] Filed Apr-28.1969 3.474.805 10/1969 Swnrtz. 137/815 X in rne l d m 3.500.848 3/1970 Kelley 137/8115 ssignee n tales Ame as Primary Exammer- Sameul Scott by d Am, Attorneys-Harry M. Snrngovitz. Edward J. Kelly. Herbert Bed and J. D. Edgerton [54] FLUERIC SELF-BIASING AND GATE 3 ABSIRACT: A flueric mo logic element is disclosed which 137/815 is cnpable of accurate and reliable operation without the 1 1 ll necessity of critical dimensional control. This is accomplished 37/8 1 by the use of a pair of fluid bias channels which produce a low pressure re "on in the vicinit of the control nozzle. in one cm- {561 cad bodiment "at; his channels Zre located between the two input UNlTED STATES PATENTS signals and the two control channels of the respective am- 3.080,886 3/1963 Severson 137/815 plifiers. In a second embodiment both bias channels feed into 3.366.131 1/1968 Swartz 137/815 1 central control channel located between the two interaction 3,369,557 2/1968 Wood 137/816 chambers 01' the respective amplifiers.

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PATENTED gun 3 Ian 3; 592, 20s

sum 1 OF 2 wvEA/ro/es, STEVE/v K/MMEL flME/Z z. SW/M/TZ 5r 2 Q/ W 7 9% I? m C FLUERIC SELF-BIASING AND GATE RIGHTS OF THE GOVERNMENT The invention described herein may be manufactured, used, and licensed by or for the United States Government for governmental purposes without the payment to us of any royalty thereon.

BACKGROUND OF THE INVENTION This invention relates generally to fluid systems and more particularly to an improved pure fluid component that will perform the AND logic function.

Pure fluid systems have recently been extensively used to perform the usual logic functions previously performed by electronic components. Their inherent ruggedness and reliability make them excellent substitutes for electronic components in environmental conditions which tend to produce shock, vibrations, or extreme temperature variations.

It has been known to use pure fluid logic circuitry to perform AND logic functions in the past, but these have not always been accurate and reliable under all circumstances. One type of fluid AND gate utilizes two input streams that impinge on one another at right angles. Another unit utilizes input streams that impinge on one another in a head on relation. These units are referred to as the crossover type AND unit and the opposed-input type AND unit, respectively. Both have the common disadvantages of turbulence, losses and occasional spurious signals as a result of the sharp turning of the streams after they interact with one another to produce the output signal. In addition, these units have relative low gain.

Another type of fluid AND element is one illustrated in US. Pat. No. 3,366,133 to Swartzv While the Swartz device overcomes some of the previously mentioned difficulties, it has the disadvantage that very precise dimensional control is required on the fluid flow passages. Typically, the Swartz device would require dimensional control to within thousandths of an inch. The invention described herein avoids the need for such critical dimensional control, without any degradation in switching gain or pressure recovery.

It is therefore an object of this invention to provide a pure fluid device for performing the AND logic function without the need for critical dimensional control.

It is another object of this invention to provide a pure fluid logic element that responds quickly and efficiently between two input signals, without direct interaction between the two signals.

Still another object of this invention is to provide an AND logic element that is reliable, simple, economical to manufacture, and has no moving parts.

SUMMARY OF THE INVENTION Briefly in accordance with this invention, a pair of fluid amplifiers are provided with a pair of fluid bias channels to afford accurate and reliable sidewall attachment. The bias channels provide a fluid flow path between the two input channels and the two control channels of the fluid amplifiers. Fluid flowing in one of the bias channels causes a reduction in pressure at that region of the control nozzle which is adjacent to the bias channel. By employing these bias channels, reliable sidewall attachment is achieved without the necessity of critical dimensional control as was required by the prior art.

BRIEF DESCRIPTION OF THE DRAWINGS The specific nature of the invention as well as other objects, aspects, uses and advantages thereof will clearly appear from the following description and from the accompanying drawing, in which:

FIG. 1 is a top view of one embodiment of the invention.

FIG. 2 is a top view of a second embodiment of the inventron.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to the drawings, the logic element 10 is shown as being the planar type and may, for example, be constructed from a series of laminae that have been cut out to provide for the nozzles, passages, and chambers by any conventional method. The device is secured by conventional screws ll.

Two input signals, designated as signal A and signal B in accordance with the usual Boolean notation, are presented to logic element 10 in the form of streams of pressurized fluid from other units (not shown). Fluid signal A enters the logic element 10 by way of an input passage 14 and issues as a stream of fluid from nozzle 15 into an interaction chamber 16. A left open control channel 17 provides fluid communication between the ambient and interaction chamber 16. A biasing slot I2 provides a fluid path between input passage 14 and left control channel 17. Interaction chamber 16 is bounded on the left by an outer sidewall 19 and on the right by an inner sidewall 20. Outer sidewall 19 of interaction chamber 16 leads into a left output receiver 21, and inner sidewall 20 leads into a central output receiver 22. Separating the left output receiver 21 and the central output receiver 22 is a divider 23.

Input signal B enters logic element 10 by way of an input passage 24 which is substantially parallel to input passage 14. Input passage 24 terminates at inlet nozzle 25 from which signal B issues as a stream of fluid into an interaction region 26. A right open control channel 27 provides fluid communication between interaction region 26 and the ambient. Biasing slot 13 provides a fluid communication path between input passage 24 and right control channel 27. Interaction region 26 is bounded on the right by an outer sidewall 29 and on the left by an inner sidewall 30. Outer sidewall 29 leads into a right output receiver 31 while inner sidewall 30 leads into the central output receiver 22. Divider 33 separates the central output receiver 22 from the right output receiver 31.

Inner sidewalls 20 and 30 of their respective interaction regions are also the sidewalls of a central triangular shaped divider 32 which separates the two interaction regions 16 and 26. Entrainment channel 34 provides fluid communication between interaction chamber 16 and interaction chamber 26 and is positioned transverse to the input passages 14 and 24. Entrainment channel 34 communicates with the ambient on the left by means of control channel 17 and left output receiver 21, and on the right by means of control channel 27 and right output receiver 31.

In the operation of the fluid AND gate of FIG. 1, a fluid signal applied to either the A or B input will issue from its respective nozzle as a stream of fluid, and will attach to the outer wall of its interaction chamber to produce an output signal in the left output receiver 21 or the right output receiver 3]. Assume that a signal is applied at the A input. The major portion of this signal will proceed through input channel 14 and into interaction chamber 16. A smaller amount of fluid will be diverted by divider 35 into bias channel 12 and will exit to ambient through left control channel 17. This flow of fluid in control channel 17 will produce a low pressure region 40 just to the left of nozzle 15. The flow of fluid from nozzle 15 into interaction chamber 16 will cause fluid to be entrained through entrainment channel 34 which is in communication with ambient by means of channels 27 and 31. The combined effect of fluid entrainment in channel 34 and reduced pressure in region 40 produces a pressure differential which causes the fluid issuing from nozzle 15 to be deflected to the left and attach to left sidewall 19 of interaction chamber 16, and to exit through left output receiver 21.

While the operation of the fluid logic element has been described with respect to the application of signal A, it will be appreciated that the arrangement works in the identical manner when only signal B is applied. Under such conditions fluid issuing from nozzle 25 will entrain fluid in channel 34. Also a portion of the fluid in inlet channel 24 will be deflected by divider 36 and will flow through bias channel 13 and out to ambient by way of control channel 27. This flow will produce a low pressure region 41, and the combined effects of low pressure 41 and entrainment channel 34 will cause the fluid issuing from nozzle 25 to attach to right sidewall 29 and exit through right output receiver 31.

The operation of the fluid logic element has been described when only a single input signal A or B is applied to the element. Now the operation of the device will be described when both signals A and B are applied. Assuming that signal A has already been applied as described above, it will be recalled that fluid will be flowing in left output receiver 21. Upon the application of signal B, fluid issuing from nozzle 25 will flow toward interaction chamber 26, thereby cutting off fluid com munication between entrainment channel 34 and ambient. As a result, fluid will no longer entrain in channel 34 and the pressure differential between channel 34 and channel 40 will be reduced. This reduction in pressure differential across inlet nozzle 15 will cause the fluid issuing from nozzle 15 to flow into interaction chamber 16 and attach itself to right sidewall 20, and thereafter exit through central outlet receiver 22. The same phenomenon will occur in the vicinity of interaction chamber 26. Fluid issuing from nozzle 25 will no longer entrain fluid in channel 34 due to the fact that fluid issuing from nozzle 15 will have cut off communication between channel 34 and ambient. Therefore, the fluid issuing from nozzle 25 will enter interaction chamber 26, attach itself to left sidewall 30, and exit through central outlet receiver 22. lt is thus seen that an output signal will appear at outlet receiver 22 only when both signals A and B are applied.

FIG. 2 shows a modification of the fluid element described in HO. 1. Assuming that signal A is applied to inlet channel 14, fluid will issue from nozzle 15 and flow toward interaction chamber 16. A portion of inlet fluid 14 will be diverted by divider 35' into bias channel 12, and will flow out to ambient through mutual control path 34. Also, fluid flowing from nozzle 15 toward interaction chamber 16 will cause fluid to be entrained in channel 17 which communicates with the ambient. The effect of fluid flowing between bias channel 12' and am bient is to produce a low pressure region 40', and the effect of fluid entrainment in channel 17 is to increase the pressure in channel 17. The result is that a fluid pressure differential is applied to nozzle 15 which causes the fluid in interaction chamber 16 to attach itself to sidewall 20. Similarly, when only fluid signal B is applied the fluid issuing from control nozzle 25 will attach itself to sidewall 30 because of the combined effect of fluid entrainment in channel 27 and flow in bias channel 13'. When both signals A and B are applied simultaneously, it will be appreciated that fluid will flow in both bias slots 12' and 13', and will meet in control path 34. This flow of fluid into control channel 34 will increase the pressure in channel 34 until it is greater than the pressure at control channel 17 and control channel 27. The increased pressure in control channel 34 will deflect the fluid issuing from both nozzle 15 and nozzle 25 and cause the respective fluids to attach to outer walls 19 and 29, respectively. Fluid will, therefore, exit from outlet receivers 51 and 54, and no fluid will appear at output receivers 52 and 53. Thus, fluid will appear at output receivers 51 and 54 whenever both signals A and B are applied, fluid will appear only at output receiver 52 when signal A alone is applied, and only at output receiver 53 when signal B alone is applied.

The signals appearing at output receivers 51 and 54 can, of course, be combined into a single outlet as shown in FIG. 1, or they may be used separately as two independent actuators if desired.

We wish it to be understood that we do not desire to be limited to the exact details of construction shown and described, for obvious modifications will occur to a person skilled in the art.

We claim:

1. A flueric element for performing an AND logic function comprising;

a. a first nozzle for issuing a stream of fluid into a first interaction chamber in response to a first fluid input signal; a second nozzle for issuing a stream of fluid into a second interaction chamber in response to a second fluid input signal;

. a first receiver in fluid communication with said first interaction chamber for producing an output signal only when said input signal is applied and said second input signal is not applied;

d. a second receiver in fluid communication with said second interaction chamber for producing an output signal only when said second input signal is applied and said first input signal is not applied;

e. means for producing an output signal when said first and second input signals are applied;

first and second entrainment channels for providing fluid communication between said first and second interaction chambers and ambient;

g. a control channel in fluid communication with said first and second interaction chambers; and

h. first and second fluid bias means for controlling the amount of fluid flow in said control channel.

2. The flueric element of claim 1 wherein said first and second fluid bias means provide a fluid flow path between said first and second fluid input signals and said first and second entrainment channels, respectively.

3. The flueric element of claim 1 wherein said first and second bias means provide a fluid flow path between said first and second fluid input signals and said control channel. 

1. A flueric element for performing an AND logic function comprising: a. a first nozzle for issuing a stream of fluid into a first interaction chamber in response to a first fluid input signal; b. a second nozzle for issuing a stream of fluid into a second interaction chamber in response to a second fluid input signal; c. a first receiver in fluid communication with said first interaction chamber for producing an output signal only when said input signal is applied and said second input signal is not applied; d. a second receiver in fluid communication with said second interaction chamber for producing an output signal only when said second input signal is applied and said first input signal is not applied; e. means for producing an output signal when said first and second input signals are applied; f. first and second entrainment channels for providing fluid communication between said first and second interaction chambers and ambient; g. a control channel in fluid communication with said first and second interaction chambers; and h. first and second fluid bias means for controlling the amount of fluid flow in said control channel.
 2. The flueric element of claim 1 wherein said first and second fluid bias means provide a fluid flow path between said first and second fluid input signals and said first and second entrainment channels, respectively.
 3. The flueric element of claim 1 wherein said first and second bias means provide a fluid flow path between said first and second fluid input signals and said control channel. 